I would recommend taking a look at a 'real-world' sample application called NerdDinner and 185-page PDF walkthrough 'how-each-line-was-written' on Code Plex .
Business Logic should be cleanly separated from Data Access; as you've correctly said, putting common objects to pass between all layers in the Data Access is bad.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.